Detergent compositions for laundering textile fabrics, containing a copolymer of a lower nu-alkyl acrylamide and vinyl alcohol



DETERGENT CQMFOSHTIONS FER LAUNDERKNG TEXTKLE FALKJRHCS, CGNTAINING A CPULY-.

MER (IF A LQJWER N-ALKYL ACRYLAMEDE AND "VINYL ALCOHOL George P. Touey and John R. Caldwell, Kingsport, Tenn, assignors to Eastman Kodak Company, Rochester, N. Y., a cor oration of New Jersey No Drawing. Application February 11, 1953, Serial No. 336,443

4 Claims. (Cl. 252-152) This invention relates to detergent compositions for the laundering of textile fabrics. More particularly, it relates to detergent compositions which not only remove soil from textile fabrics, but prevent redeposition of the soil on the fabrics during the laundering operations.

In the wet laundering of textile fabrics, the effectiveness of the detergency action is dependent upon two factors: removal of the soil from the fabric, and prevention of redeposition of the soil on the fabric before the laundering cycle is completed. Synthetic detergents are known to be excellent dispersing and cleaning agents; however, in the laundering of textile fabrics they are incapable of preventing a portion of the removed soil from redepositing on the fabric. In the case of dyed fabrics, the redeposited soil results in a considerable loss of the original brightness. In the case of white fabrics, it prevents restoration of their full whiteness.

A number of substances have been tested as adjuvants in detergent compositions, for preventing soil redeposition. Armstrong et 211., American Dyestutf Reporter 37, 596 (1948), have compared polyvinyl alcohol, methyl cellulose, potato dextrin, chrome glue, cornstarch, bentonite, and sodium carboxymethylcellulose in their effectiveness for this purpose. With the exception of sodium carboxymethyleellulose, however, none of these substances has found general acceptance in the trade.

Although carboxymethylcellulose is moderately effective for preventing soil redeposition in the laundering of cotton fabrics, it sulfers the disadvantage of being ionic in nature, and is readily precipitated by salts of diand polyvalent metals such as calcium, magnesium, zinc, iron and aluminum. It is therefore adversely affected by hard water. Moreover, even in soft water, it does not prevent redeposition of soil in the laundering of cellulose acetate, nylon or wool.

We have discovered that the addition of copolymers of lower N-alkyl-acrylamides and vinyl alcohol to anionic or non-ionic detergents prevents redeposition of soil on textile fabrics when the fabrics are washed with these detergents. In the term anionic detergents, we mean to include soap as well as the synthetic anionic detergents.

The copolymers of lower N-alkyl-acrylamides and vinyl alcohol have the general structure The ratio of n to m lies in the range of 1 :1 to 10:1; X =50 to 1000. R is a lower alkyl group. These copolynited States Patent mers are advantageously prepared from (emulsion) copolymers of a methacrylate and vinyl acetate. They may contain 30-80% of alkacrylate. Preferably, 4060% of alkacrylate is employed. The copolymer of alkacrylate and vinyl acetate is heated with 2-5 parts of, for example, methyl, ethyl, or isopropyl alcohol containing 0.5-2 parts of an amine or ammonia ammonolysis reagent. The ammonolysis reaction preferably is carried out in a pressure vessel equipped with agitating means at 80120 C. for 2-4 hours. I

The copolymer of lower N-alkyl-acrylamide with vinyl alcohol derived by the ammonolysis procedure is isolated by evaporation of the solvent or by pouring the solution into a precipitant such as benzene or isopropyl ether. Suitable ammonolysis reagents include various amines such as monomethyl, monoethyl, mono-isopropyl, and monobutyl amines. Cyclic amines such as morpholine, piperidine, and pyrrolidine may also be employed. The lower aliphatic amines, however, are advantageous, since with them a high conversion to the corresponding N- alkyl-acrylamide is obtained. The conversion ordinarily is in the range of 50-90%, and the products in most cases are soluble in water.

The lower N-alkyl-acrylamide-vinyl alcohol copolymers may also be prepared by hydrolyzing the acetyl groups from lower N-alkyl-acrylamide-vinyl acetate interpolymers. For example, an interpolymer containing 75% N-isopropyl acrylamide-25% vinyl acetate may be selectively hydrolyzed by known methods, using dilute sulfuric acid, to remove the acetyl groups but-leaving the N-isopropyl amide groups unchanged. The hydrolysis may be carried out in alcohol, water, or other suitable medium. Ammonium hydroxide or amines at 25-100 C. are especially suitable for the selective hydrolysis. Sodium carbonate or sodium hydroxide may be used. Interpolymers of vinyl acetate with the following amides may, for example, be used: N-methyl acrylamide, N- ethyl acrylamide, N-isopropyl acrylamide. The interpolymers 'may contain from 20 to vinyl acetate, and preferably 40 to 60% vinyl acetate before hydrolysis.

Our novel detergent compositions are mixtures of copolymers of lower N-alkyl-acrylamides and vinyl alcohol, with a detergent selected from the group consisting of the anionic detergents, including soap, and the non-ionic detergents, in ratios ranging from 1 part copolymerz99 parts detergent to 25 parts copolymer: parts detergent. Although higher proportions of the copolymer can be used, the improvement in the cleaning power was found to reach a maximum at 25 parts copolymer:75 parts detergent. Improvement in detergency was noticeable at a ratio of 1 part copolymerz99 parts detergent. However, the most desirable range is from 2 parts cop0lymer:98 parts detergent to 10 parts copolymer: parts detergent.

Using the following types of detergents, we have found that a mixture of parts by weight of detergent and 5 parts by weight of lower N-alkylacrylamide-vinyl alcohol copolymer gives better detergency than parts by weight of the same detergent:

1. An alkyl sulfate (anionic) 2. An alkyl sulfonate (anionic) 3. An alkyl-aryl sulfonate (anionic) 4. A sulfonated amide (anionic) 5. A fatty acid-polyethylene glycol condensate (nonionic) 6. A phenol-polyethylene glycol condensate (non-ionic) 7. An alcohol-polyethylene glycol condensate (nonionic) 8. A mercaptan-polyethylene glycol condensate (nonionic) 9. A polypropylene glycol-polyethylene glycol condensate (non-ionic) 10. Soap (anionic) The improvement obtained by the substitution of the lower N-alkylacrylamide-vinyl alcohol copolymers for a portion of a detergent (or detergent-builder combination) varies according to the efiiciency of the original detergent formulation. For example, by means of these copolymers it is possible to improve anionic type synthetic detergents to the point wherethey are equalorsuperior to soap in their ability to prevent soil redeposition during the laundering of textile fabrics. These copolymers also improve soap alone or soap alkaline builder formulations. In-general, therefore, it can be said that by the substitution of these lower N-alkylacrylamide-vinylalcohol co-' polymers for a small portion of a detergent formulation in which the detergent is selected from the group consisting of the anionic detergents, including soap, and the non-ionic detergents, a remarkable improvement is obtained in the ability of the detergent formulation to prevent soil redeposition.

The mechanism by which these copolymers function as detergent adjuvants is still to be determined. One possible explanation is that the copolymers are selectively adsorbed on the fabric, building a charge that repels the dirt particles after they have once been removed from the fabric. Another explanation is that the copolymers function as soil-suspending agents. Although these copolymers have soil-suspending properties, this mode of action cannot be considered to be the only explanation of their ability to prevent soil redeposition. A large number of water-soluble polymers are known to be excellent suspending agents, yet they do not possess the detergency properties exhibited by either sodium carboxymethylcellulose or the copolymers herein described. This is shown bythe following example.

EXAMPLE 1 A detergent solution containing suspended carbon soil was prepared by dispersing 14 grams of Aquablak-B (a 35% aqueous suspension of carbon black, manufactured by Binney & Smith Company, New York, New York) in 11 liters of water containing 25 grams of Igepon T (a sulfonated amide, anionic type detergent, having the formula C17H33CON(CH3)C2H4SO3Na). Several 100- ml. portions of this stock solution were removed, and to all but one (control) of these portions there was added 0.0125 g. of a water-soluble polymer selected from the list shown in the table below. Thus the weight of adjuvant was approximately of the weight of detergent, in each sample. The solutions were transferred to standard Launder-O-Meter bottles (pint size), each containing steel balls, A in diameter. The bottles of detergentsoil solutions were preheated to 140 F., and a 2%." x 3 /2" piece of clean cotton broadcloth was placed in each bottle. The bottles were sealed and tumbled for 30 minutes at 140 F. inanAtlas Launder-O-Meter. The cloth samples were then removed from the soil solutions, rinsed in warm water, and dried. Reflectance curves were obtained for each washed cloth sample by means of a General Electric recording spectrophotometer. The average percent reflectance values were calculated for the curves. These'valueswere then converted to percent whiteness retained by means of the following formula:

Percent whiteness retained X 100 Rw=average reflectance of the cloth laundered 1n the soil solut1on Ro=reflectance of the white broadcloth before launder- Table I shows the results of these tests.

Table 'I [Detergent- Igepon T.]

Percent Whiteness Retained Adjuvant by the Laundered Cloth None 22 Sodium carboxymethylcellulose 61 66 N -Methylacrylamide34 vinyl alcohol, copolymer 74 N-Methylacrylamide20 vinyl alcohol, copolymer. 82 Hydroxyethylcellulose (Cellosize). 30 Methylcellulose (Methocel) 31 Cornstarch 13 Dextrin 14 Pectin (citrus) 49 Sodium alginate (Kelgln) 9 Propylene glycol alglnate (Kelcoloid) 44 Locust bean gum 38 Mesquite gum. 44 Gum arable 45 Polyvinyl alcohol (Elvanol) 24 Dextran (unhydrolyzed) 20 Sodium salt; of maleic acid-styrene copolymer (Sodium Stymer) 1 1 12 Sodium vpolyacrylate. 25 Polyvinyl pyrrolidou 17 Sodium salt of 50 male isopropenyl acetate 0 polymer 25 70 Acrylic acid30 acrylonitrile oopolymer 18 Poly-N-isopropylacrylamide 35 Poly-N -isopropy1methacrylamide 31 72 N-Methylacrylamide-28 allyl alcohol copolymer 21 Bentonite 26 It will be seen that the lower N-alkyl-acrylamide-vinyl alcohol copolymers gave better results than any of the other adjuvants in preventing soil deposition, even giving improved results as compared to sodium carboxymethylcellulose.

The following example illustrates how three detergents are improved by substituting, for 5% of the detergent, copolymers of N-methylacrylamide-vinyl alcohol (X =500).

EXAMPLE 2 A series of detergent solutions were prepared, having the compositions shown in Table 11, so that the total concentration of detergent formulation in each was 0.25%, and the adjuvant portion of the detergent formulation was 0.0125 g., or approximately 5% based on the detergent weight. In ml. of each of the detergent solutions, a 2 /2" x 3 /2" swatch of standard soiled cotton broadcloth (P. S. C. soiled cotton, sold by Foster D. Snell, Inc., New York, N. Y.) was laundered for 30 minutes at F., using an Atlas Launder-O-Meter and 10 steel abrasion balls. The laundered swatches were rinsed in distilled water at 140 F., and the laundering cycle was repeated. After three successive washings the laundered swatches were ironed and dried. Reflectance curves were then obtained for each cloth-sample, using a General Electric recording spectrophotometer. This data was converted to percent whiteness regained values by means of the formula:

P R.,,R,

ercent whiteness regained- X 100 Rw=percent reflectance of the soiled swatch after washing Rs=percent reflectance of the soiled swatch before washing (27% i 1% Ro=percent reflectance of the unsoiled swatch 5 The results are shown in Table II.

Table II.Sil rem0valC0tton Detergent Formulation (Grams dissolved material in Percent 100 ml. distilled water) whiteness regained 0.25 g. Igepon T" (control) 27 0.24 g. Igepon T+0.0125 g. N a-carboxymethyl cellulose 35 0.24 g. Igepon T+0.0125 g. 66 N -methy1-acrylamide34 vinyl alcohol copolymer 37 0.24 g. Igepon T+0.0l25 g. 80 N-methyl acrylarnide20 vinyl alcohol copolymer l 38 0.25 g. Kreelon 4D* (control) 22 0.24 g. Kreelon 4D+0.0l25 g. Na-carboxy-methyl cellulose- 32 0.24 g. Kreelon 4D+0.0125 g. 66 N-methyl-acrylamide34 vinyl alcohol copolymer 32 0.24 g. Kreelon 4D+0.0125 g. 80 N-methyl-aorylamide-20 vinyl alcohol copolymer 31 0.25 g. Duponol ME* (control) 29 0.24 g. Duponol ME+0.0125 g. N a'carboxy-rnethylcellulose. 39 0.24 g. Duponol ME+0.0125 g. 66 N -rnethyl-acrylamide34 vinyl alcohol copolymer 38 0.24 g. Duponol ME+0.0l25 g. 80 N-methyl-acrylamide20 vinyl alcohol copolymer 38 0.25 g. Ivory soap* (control) 39 0.24 g. Ivory soap+0.0125 g. N a-carboxy-methylcellulose. 48 0.24 g. Ivory soap+0.0l25 g. 66 N-methyl-acrylamide-34 vinyl alcohol copolymer 49 0.24 g. Ivory soap+0.0l25 g. 80 N-methyl-acrylamide-20 vinyl alcohol copolymer 50 0.25 g. Igepal OA* (control) 30 0.24 g. Igepal CA+0.0125 g. Na-carboxy-methylcellulose 38 0.24 g. Igepal CA+0.0125 g. 66 N-methyl-acrylamide34 vinyl alcohol copolymer 36 0.24 g. lgepal OA+0.0125 g. 80 N-methyl-acrylamide20 vinyl alcohol copolymer 40 *Igepon T is a sulfonated amide. anionic type detergent, having the formula C17HssCON(CHs)C2H4SOBN&, manufactured by General Dyestuff Corp. Kreelon 4D is a sodium alkylaryl sulfonate type anionic detergent, manufactured by the Wyandotte Chemicals Corp. Duponol ME is a fatty alcohol sulfate anionic detergent (technical sodium lauryl sulfate), manufactured by E. I. du Pont de Nemours & Co. Ivory Soap is a sodium soap of vegetable oil fatty acids, manufactured by Proc er 8; Gamble. lzepal CA is a non-ionic polymerized ethylene oxide condensation product, manufactured by General Dyestuif Corp.

It will be seen that the N-alkylacrylamide-vinyl alcohol copolymers gave results equal to those given by sodium carboxymethyl cellulose, as to soil removal.

EXAMPLE 3. WHITENESS RETENTION TESTS This example illustrates the ability of the copolymers of N-methylacrylamide-vinyl alcohol, in which X=600, to prevent wet soil deposition on cotton, nylon, cellulose acetate, and wool.

Clean 2 /2 x 3 /2" swatches of cotton, nylon, cellulose acetate, and wool were separately laundered in freshly prepared detergent-soil solutions as listed in Table III. Each solution contained 100 ml. Water, 0.25 g. detergent, 0.14 g. Aquablak-B, and 0.0125 g. adjuvant adjuvant based on the weight of detergent), with the exception of the control solutions, which contained no adjuvant. Only one laundering cycle was employed. This was carried out in an Atlas Launder-O-Meter at 110 B, using the standard pint jars and steel abrasion balls in each jar. After a 30-minute treatment, the swatches were removed and separately rinsed in clean water at 110 F. When dry, the samples were ironed.

Reflectance values were obtained for each of the washed and ironed samples by means of a General Electric recording spectrophotometer. These values were substituted in the formula m XlOO to obtain the percent whiteness retained for each cloth sample. The results are shown in Table III.

Percent whiteness Retained Detergent Solution (Grams dissolved material in 100 ml. water) Fabric 0.25 g. Kreelon 4D (Control) Do Do 0.25 g. Kreelon 4D+0.0l25 g. N a-carboxymeghylcellulo se.

Do 0.25 g. Kreelon 4D+0.0l25 g. N-methylacrylamide-20 vinyl alcohol, copol- Do 0.25 g. Nacconol NR+0.0125 g. Na-

cafiaoxymethylcellulose.

D0 0.25 g. Nacconol+0.0125 g. 80 N-methylacrylamide-20 vinyl alcohol, copoly- 0.25 g. Ivory soap+0.0125 g. N a-earboxymethylcellulose.

o IIIIIIIIIII 0.25 g. Ivory soap+0.0l25 g. 80 N -methylacrylamidc-2O vinyl alcohol copoly- Do Wool Nacconol NR is an alkyl aryl sodium sulfonate anionic detergent manufactured by the National Aniline Division of the Allied Chemical & Dye Corp.

The nylon cloth used in this example was made of desized, delustered taffeta filament, and was obtained from Test Fabrics, Inc. The cellulose acetate cloth was broadcloth weight, made of plain spun staple. The wool cloth was broadcloth weight, plain weave, obtained from Test Fabrics, Inc. The cotton cloth was Indian Head domestic broadcloth.

As Kreelon and Nacconol are the same type of detergent, namely an alkyl aryl sodium sulfonate, it would be expected that similar results would be obtained with them, and it will be observed from Table III that this is the case. In the case of cotton, with the detergents, great improvement was brought about by the use of sodium carboxymethylcellulose, and even greater improvement by the use of the copolymer; with soap, some improvement was brought about by the use of sodium carboxymethylcellulose, and much greater improvement by the use of the copolymer. In the case of nylon, with the detergents, no improvement was brought about by the use of sodium carboxymethylcellulose, whereas considerable improvement was brought about by the use of the copolymer; with soap, a slight improvement was brought about by the use of sodium carboxymethyl cellulose, and a great improvement by the use of the copolymer. In the case of cellulose acetate, with the detergents, a slight improvement was brought about by the use of sodium carboxymethyl-cellulose, and a great improvement by the use of the copolymer; with soap, which gave good results in the control, there was little change when either adjuvant was used. In the case of wool, with the detergents, no improvement was given by the use of sodium carboxymethylcellulose, whereas some improvement was given by the use of the copolymer; with soap, which gave good results in the control, a slight improvement was given by wherein the ratio of n to 1;; lies in the range of 1:1 to :1, and X :50 to 1000, the ratio by weight of copolymer .to detergent being in the range from 1:99 to 25:75.

2. A detergent composition comprising an organic anionic detergent and a copolymer of vinyl alcohol and a N-alkyl acrylamide in which the alkyl group contains from 1 to 3 carbon atoms, the copolymer having the general structure wherein the ratio of n to m lies in the range of 1:1 to 10:1, X =50 to 1000, and R is an allgyl group of from 1 to 3 carbon atoms, the ratio by weight of copolymerto detergent being in the range from 1:99 to 25 :75.

3. A detergent composition comprising an organic anionic detergent and a copolymer of N-ethylacrylamide and vinyl alcohol, the copolymer having the general structure lzHr wherein the ratio of n to m lies in the range of 1:1 to 10:1, and X= to 1000, the ratio by weight of copolymet to detergent being in the range from 1:99 to 25:75. 4. A detergent composition comprising an organic anionic detergent and a copolymer of N-isopropylacrylamide and vinyl alcohol, the copolymer having the genwherein the ratio of n to m lies in the range of 1:1 to 10: 1, and X 510 to 1000, the ratio by weight of copolymer to detergent being in the range from 1:99 to 25:75.

e e nc s Cited n th fil of t pa N TED ST TES E S 2,476,527 Barnes et a1 July 19, 1949 2,486,241 Arnold Oct. 25, 1949 FOREIGN PATENTS 950,6515 France Oct. 3, 1949 

1. A DETERGENT COMPOSITION COMPRISING AN ORGANIC ANIONIC DETERGENT AND A COPOLYMER OF N-METHYLACRYLAMIDE AND VINYL ALCOHOL, THE COPOLYMER HAVING THE GENERAL STRUCTURE 